public class Abstract {
    public static void main(String[] args) {
        Person person1 = new Student();
        person1.run();

        Person person2 = new Teacher();
        person2.run();
    }
}
abstract class Person{
    public abstract void run();
}
class Student extends Person{
    @Override
    public void run() {
        System.out.println("疯狂地跑");
    }
}
class Teacher extends Person{
    @Override
    public void run() {
        System.out.println("优雅地跑");
    }
}
